Research On Polymorphism Of α(1,2) Fucosyltransferase (FUT1) Gene And Its Association With Litter Size In Pig

Abstract Ehterotoxigenic Escherichia coli F18 (ECF18) is a main pathogen that causes edema disease and post-weaning diarrhoea in piglets, and a(l,2)fucosyltransferase(FUT1) gene has been identified as a candidate gene for controlling the expression of the receptor for ECF18 bacteria. The genetic variations at position 307 nucleotide in open reading frame of FUT1 gene in 6 pig breeds (total 245 individuals) from 3 Exotic pig breeds and 3 Chinese native pig breeds were investigated by PCR-RFLP. The association between different genotypes of the FUT1 gene and its resultant litter sizes were evaluated by statistic analysis to test weather the FUT1 gene can be a genetic marker affecting litter sizes or tightly linked with it.The results showed that the genetic polymorphisms of the FUT1 locus were only detected in 3 Exotic pig breeds, 3 Exotic pig breeds possessed 3 different genotypes ; The frequency of A,G allele was 0.25 and 0.75 respectively.It infered that the mutation frequency is lower.All Chinese native pig breeds only presented the susceptible genotype GG. The results indicated that M307 G → A point mutation in the coding region of FUT1 gene might be the key factor determining the expression of the ECF18 receptor , Chinese native pig breeds were absent of the genetic background on the resistance to ECF18 bacteria.The genotype distribution of FUT1 gene between exotic pig breeds and Chinese native pig breeds is signaficantly different by Chi-square test. The test of Hardy-Weinberg equilibrium of exotic pig breeds showed that Large White much diverged from the genetic equilibrium (P<0.01).The results suggested that further study should be done to identify and characterize putative QTL (quantitative trait locus) and the functional gene responsible for the resistance to ECF18 in Chinese native pig breeds.Population genetics analysis consequence showed that the locus of 3 Exotic pig breeds existed medium polymorphism.Univariate analysis of variance components indicated that FUT1 gene and breeds influence significantly total number born, parities influence total number born unsignificantly. FUT1 gene,breeds and parities influence unsignificantly the litter size alive. It is necess parities influence unsignificantly ary to identify the research result by improve sample number.